Avalanche concerns increase with expected Thursday storm

BACKCOUNTRY BEWARE The avalanche danger in the Sea to Sky area varies from High to Moderate into Tuesday.

Following a 20cm snowfall on Sunday night, avalanche forecasters are once again suggesting the risk of serious backcountry avalanches will rise in the coming days.

The Whistler Blackcomb Backcountry Avalanche Advisory was updated today (Tuesday) and predicts the avalanche risk in the alpine will move from Considerable to High on Thursday, Feb. 28.

“Cornices have grown and are breaking easily,” noted the advisory. “Stay well back and give them a wide birth.”

The advisory has indicated that a recent large cornice fall was remotely triggered by the weight of a skier who was well back from the edge.

Avalanche control on WB Feb. 25 produced mostly size one avalanches with a size 2.5 observed on Whistler Mountain’s Hanging Roll. Loading from snow that fell Sunday night and high winds contributed to that snow slide.

“All these slides appeared to be moving on old surfaces and within the storm layers,” reported the advisory.

The freezing level is expected to rise as a warm front approaches, which is expected to bring heavy precipitation on Thursday.

The Canadian Avalanche Centre (CAC) is working with less information for its bulletin due to a lack of reports on conditions in backcountry areas around Squamish, Pemberton and the rest of the Sea to Sky corridor. The CAC danger ratings are exactly the same as the advisory posted by WB.

Sunday, Feb. 24 report

The avalanche danger rating in alpine areas for Sunday and Monday ranges between moderate to high in the Sea to Sky area.

The Whistler Blackcomb report indicates moderate risk rising to considerable Monday and Tuesday while the Canadian Avalanche Centre (CAC) is suggesting the rest of the Sea to Sky corridor carries a high risk with the rating easing down to considerable Monday and Tuesday.

The CAC has indicated that the new snow from the last few days may require a few days to settle and stabilize. The centre also cautions anyone bold enough to go into the backcountry to transition into wind-affected terrain with care.

The WB report has indicated notable avalanches were triggered with explosives Saturday in the ski area.

Tim Jones of the North Shore Search and Rescue has been discouraging people all weekend to stay out of the backcountry in his area due to avalanche danger conditions that he described as very dangerous.

Friday, Feb. 22 report

A storm system that moved through Whistler on Friday has elevated local avalanche conditions in the Whistler Blackcomb alpine backcountry, from "Low" to "Considerable" through the weekend according to the latest bulletins.

Considerable means that natural avalanches are possible and human-triggered avalanches are likely, and caution is recommended when evaluating the snowpack, picking routes and making decisions.

In the surrounding Sea to Sky region, the Canadian Avalanche Centre has pegged the avalanche risk at "High," which means that natural avalanches are likely and human-triggered avalanches are very likely. Travel in avalanche terrain is not recommended.

While welcome, the new snow is sitting on a layer of crust, hard slabs and rocks that have been exposed in the recent drought and warm weather conditions. It will take some time for the new snow to bond with the layer underneath.